Middle 1.5 cm of anal canal is lined by

The anal canal is divided into three pas. The zona columnaris is the upper half of the canal and is lined by simple columnar epithelium. The lower half of the anal canal, below the pectinate line, is divided into two zones separated by Hilton's white line. The two pas are the zona hemorrhagic and zona cutanea, lined by atratified squamous non keratinized and stratified squamous keratinized. ref - BDC vol2 pg416